.22 Mag Results in fps

An additional note on the .22 Mag (officially, the
.22 Winchester Magnum Rimfire) data: this sequence of tests presented a real challenge for our
chronographs, probably because the .22 Mag is one of the smaller bullets commercially used yet is
driven at high speed. Modern chronograph technology is based on optical sensors used to determine
the period of time a bullet takes to pass between two sensors. The smaller the bullet, the harder
it is for the optical sensor to detect it, and the more necessary it is to get the bullet exactly over
the sensor's field of vision. For most of the test we were confident that our results were
accurate, and if you look at the raw data sheets you will see that we were able to usually get four or
five 'good' readings (out of six possible - three shots each over a pair of aligned chronographs).
However, towards the end of the tests (when the barrel was starting to get very short) accuracy became
an increasingly difficult proposition. At that point we switched to a more expensive Oehler brand
chrono system, which uses twin chronographs to automatically calculate one reading. For the last
measurements in the chop tests - when the barrel was only 2" - we were only able to obtain one or two
readings for each type of ammo. The readings were consistent with the curves we had seen through
the rest of the testing, but doesn't have the same degree of supporting data.

Other Resources

BBTI is not the end-all of ballistics testing, just one more component
available for the common good. In addition to extensive discussion
about ballistics to be found at many gun forums, here are some other great
resources pertaining to ballistics testing you should check out. (And
if you would like to recommend a site to list here, please send an email.)

BrassFetcher:
excellent resource, with an emphasis on bullet performance in ballistic
gelatin

Terminal Ballistics
Research: Specializes in the research of cartridge & projectile performance,
using hard data gathered from 20 years of hunting game.

Acknowledgements

We'd like to personally and specifically thank Pat Childs at Fin & Feather in Iowa City, as he not only helped get most of our
ammunition and other supplies, he was the brilliant gunsmith who worked with us to make
this insane project much more practical. Without his help all of this would have
been much more difficult and perhaps impossible. Anyone who uses our data owes him
a debt of gratitude.

And thanks to our spouses, who were not just tolerant but enthusiastically supportive
of this rather nutty project.

Disclaimer

This project, and all of its results, is only our fault. We (well, Jim K,
mostly) paid for everything ourselves, and we did not receive any kind of sponsorship
or remuneration from anyone. We did all the work. We used products we
were either familiar with, or because they were what was available, and mentioning
them by name does not constitute an endorsement of any kind. Furthermore, the
data is provided purely for entertainment purposes - to better facilitate arguments
over what ammo or caliber or gun is "best." How you use the data is entirely
up to you. And if you think you could do better, feel free to spend the money
and do the work and publish your own results. Or not. Your choice.